I want to buy a new game for the gamecube but I don't know which one I should buy, I already have the best games that are released (RE4 (great) - PSO I&II&III - TOS - SSBM)
Are there any games you can recommend me (cool/fun multiplayer is better)
I love multiplayer games too.
I really liked Mario Kart.
How about Soul Calibur II (if you don't mind silly costumes >:p) ?
Could wait for the new Zelda if you're into RPGs.
any other good/fun (multi-p) games?
I found Mario Golf to be good, not as good as the old one for N64 though because they basically removed the need to think in it.
As for multiplayer games... Mario Kart is certainly a good choice for multiplayer. A First-Person Shooter may be a good choice for multi-player as well like Time Splitters 2 or something, but other than that I can't really think of much.
I love Sonic Games... SO get a Sonic Game
are they any good? please tell me more about those sonic games
Wow, those four games make a perfect collection as they are!
Multiplayer games eh? Why not try 1080 Avalanche (Snowboarding) or F-Zero GX (Stupidly Fast Racing), or maybe even WWE Day of Reckoning/2 if you're into wrestling games

Of course there is Mario Kart: Double Dash!! which many other people have stated, or Mario Party for multiplayer fun

Well there are three Sonic games. Sonic Adventure, Sonic Adventure 2 and Sonic Heros. Sonic Adventure 2 is the best one in my opinion. It's basically a game with fast paced action stages trying to zoom through, blast through, or find your way through the stages. There are 3 kinds of stages:
High-Speed Stage (Sonic and Shadow)
Mass Destruction Stage (Tails and Eggman)
Emerald Hunt Stage (Knuckles and Rouge)
The game will last you awhile because even after finishing the story there are 4 more missions for each stage and you have to A Rank them all in order to unlock a bonus stage and some extra goodies.
Sonic Adventure is similar, but there are only three missions for each stage making it generally shorter. Plus it is slower paced... and includes some annoying stage types. This game has 6 stage types:
High-Speed Stage (Sonic)
Race Stage (Tails)
Emerald Hunt Stage (Knuckles)
Fishing Stage (Big) <-- I hate those SO much...
Escape the Robot Stage (Amy) <-- Kinda like Sonic stages at 1/2 speed
Mass Destruction Stage (E102-Gamma)
Both the above games have the Chao Garden to deal with, but that's a whole different topic and can be finished with some patience.
The last game is Sonic Heros. It's good in its own way, but the gameplay is altered moderately. The game has 4 teams which gives you 4 different stage types:
Easy, short-length Stages (Team Rose) <-- This team will annoy you...
Medium length and difficulty Stages (Team Sonic)
Long and difficult Stages (Team Dark)
Quest Stages (Team Chaotix) <-- These can be weird sometimes.
Unfortunately all 4 teams play in the same stages unlike in the previous two games. The stages are all fairly fast paced except for a select few Team Chaotix quests, but the 3 people at once form of gameplay can make things awkward. One big bonus about this game is that there is no Chao Garden, but there is only 1 extra mission for each stage. The extra missions are always the same:
Collect 200 Rings (Team Rose)
Beat the Time Limit (Team Sonic) <-- Always my favourite
Destroy 100 Enemies (Team Dark)
Harder version of the Quest (Team Chaotix)
You have to get all A Ranks in order to unlock one last mode in this game, so you'll still have a fair bit of work to do. The game took me around 23 hours to beat, so it still isn't all that long.
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Well that's my speech on the Sonic games. If you need any more info on something more specific just ask. I had some time to waste so this speech did the trick.
Ty, btw what is this new game called Sonic gem collection or something?
And from the above everybody here says Sonic Adventure is the best?
multip game BURNOUT 1 AND 2 CAN'T BE BEATEN (except in speed by F-zero gx) the its not sonic gem collection its sonic MEGA collection